Is the role of the Shrike intended to be a "stealth missile ambusher?" If so, how many missiles can it lock and launch simultaneously?

The Shrike's role could be described as that and, compared to non-missile focused ships, it will be able to lock and launch more missiles when the revised missile locking system comes online in a future patch. Ultimately, the exact amount will be controlled by the ship's computer and can be upgradeable via blades, though dedicated missile ships will support more by default.